An analytical model for heat transfer in a pin-bundle presentation and first validation

The ANACONDA mathematical model presented here is aimed at calculating the three dimensional temperature field inside a LMFBR rod-bundle cooled by forced convection. In this thermal model the cross section of the rod bundle is discretized into a number of fluid and solid regions (pin heating zones, claddings, hexagonal duct). The lateral operators representing transverse energy transport inside the rod bundle (i.e. at a given cross-section) are approximated so as to enable an integration by hand of the thermal balance set of equations without any discrete representation of the axial space or time operators. The first validation of the model was done through calculating the three dimensional enthalpy field inside a 19 pin bundle, which had been experimentally investigated by the CEA in Grenoble (GR 19I bundle). The model was then used for the preparation of the SCARLET II local porous blockage experiments to the run by EDF at Chatou. Both sets of calculations were run rapidly on a pocket programmable calculator, and their results bring a good confidence in the validity of the model